Credit

Caption

False colour radio image of quasar 3C 273 at a wavelength of 73 centimetres. Some 2100 million light years away, 3C 273 is the nearest known quasar; it is moving away from us at a velocity of 50,000 km per second. Its most distinctive feature is its enormous jet, which extends an estimated 1.2 million light years. The end of the jet (bottom right) is as powerful a radio emitter as the quasar's core (top left). The colours represent intensity of radio emission, ranging from white (highest intensity) through to deep red (lowest). The picture was recorded by Jodrell Bank's MERLIN network of radio telescopes in north-west England.